From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Weimer Subject: Re: d_off field in struct dirent and 32-on-64 emulation Date: Thu, 27 Dec 2018 19:09:11 +0100 Message-ID: <87pntmu9iw.fsf@mid.deneb.enyo.de> References: <87bm56vqg4.fsf@mid.deneb.enyo.de> <957967d7-5717-8ada-fb30-dfdf19898b6b@linaro.org> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <957967d7-5717-8ada-fb30-dfdf19898b6b@linaro.org> (Adhemerval Zanella's message of "Thu, 27 Dec 2018 15:58:47 -0200") Sender: linux-kernel-owner@vger.kernel.org To: Adhemerval Zanella Cc: linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, libc-alpha@sourceware.org, qemu-devel@nongnu.org, ericvh@gmail.com, rminnich@sandia.gov, lucho@ionkov.net, hpa@zytor.com, arnd@arndb.de List-Id: linux-api@vger.kernel.org * Adhemerval Zanella: > Also for glibc standpoint, although reverting it back to use getdents > syscall for non-LFS mode might fix this issue for architectures that > provides non-LFS getdents syscall it won't be a fix for architectures > that still provides off_t different than off64_t *and* only provides > getdents64 syscall. > > Currently we only have nios2 and csky (unfortunately). But since generic > definition for off_t and off64_t still assumes non-LFS support, all new > 32-bits ports potentially might carry the issue. For csky, we could still change the type of the non-standard d_off field to long long int. This way, only telldir would have to fail when truncation is necessary, as mentioned below: >> There is another annoying aspect: The standards expose d_off through >> the telldir function, and that returns long int on all architectures >> (not off_t, so unchanged by _FILE_OFFSET_BITS). That's mostly a >> userspace issue and thus needing different steps to resolve (possibly >> standards action).